Note: Unless you are using a severely outdated operating system or CPU, you most likely want to always download the x64 (64-bit) version of Ultimate Doom Builder.
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
All recent versions
Ultimate Doom Builder R4248
25 Oct 2025
Fixed an issue where polyobjects were erroneously reported to have no polyobject start spot of any kind the the Eternity Engine game configuration. Fixes #1221
Ultimate Doom Builder R4242
20 Sep 2025
Script Editor: fixed a crash when the script contains malformed named script definitions. Fixes #1239
Ultimate Doom Builder R4241
26 Jul 2025
Eternity Engine UDMF Game Configuration: fixed the "friction" UDMF property for real this time (hopefull)
Ultimate Doom Builder R4240
26 Jul 2025
Eternity Engine UDMF Game Configuration: fixed the "friction" UDMF property not showing up
Ultimate Doom Builder R4239
06 Jul 2025
Eternity Engine UDMF Game Configuration: fixed a problem where the ypanningfloor sector property was not stored correctly when being edited through the Edit Sector dialog. Fixes #1217